T Cell Receptors (TCRs) are specialized proteins found on the surface of T cells, a type of white blood cell crucial for the immune system. TCRs recognize and bind to specific fragments of antigens, which are molecules from pathogens like viruses or bacteria. This interaction helps T cells identify and respond to infected or abnormal cells. When a TCR binds to an antigen, it triggers the T cell to activate and proliferate, leading to an immune response. There are two main types of T cells: CD4+ T cells, which help coordinate the immune response, and CD8+ T cells, which directly kill infected cells.